Having ordered this game almost a year ago I couldn't wait for it to arrive, when it did I couldn't help being disappointed. The graphics and storyline were fine, but what really let it down for me were the controls. There's been so much advertising about this game, especially how it was "especially created for the xbox 360", and how the controls were so good. They really weren't. After a few hours I could successfully command my army and build a base effectively, but I honestly preferred C&C red alert 3 controls, much easier and more economical. Sure, you get all your favourite units from Halo 3 but, it just didn't feel as exciting, having said that, the levels were interesting and varied, albeit quite short, especially compared to other strategy games.
On a closing note, the music was fantastic, there seemed to be loads of it and it changed depending on how much danger you were in. If you are a fan of Halo and/or strategy games, then buy it, it is good fun, just don't expect to be overwhelmed by it's greatness, as Microsoft obviously think you will be.